Clutch control mechanism



K. A. sYLvEs'TER CLUTCH CONTROL MECHANISM April 23,` 1940.

Filed March l2, 1938 NN. m0.

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I INVENTOR. KIMMEL A. SYLVESTER wm., NO.

A ORNEY.

Patented Apr. 23, 1940 l 2.198.321 cLU'ron coNTaonMEcnAnlsM Kimmel A. Sylvester, Des Plaines, Ill., assigner, by mesne assignments. to Teletypesetter Corporation, a corporation of Delaware Application March 12,

15 Claims.

This invention relates to tape controlled apparatus and particularly to a, mechanism for arresting and restarting the apparatus in response to conditions of tautness or slackness in the control tape.

An object of the invention is to provide entirely mechanical apparatus by means of which a control tape having relatively low resistance to tearing is enabled to control the transmission of a relatively large amount of power to the apparatus which the tape controls.

'I'he invention features a power transmitting clutch mechanism the load upon which is relatively small and which, therefore, may be controlled by a signal storage tape of the usual material, the clutch transmitting power to control a working or operating clutch the loads upon which are relatively severe as compared with the load upon the first mentioned clutch.

The invention also features a positive drive half-revolution clutch which is controlled in a manner similar to the operation of escapement mechanisms.

Briefly, the invention contemplates a continu-` ously operable power shaft to which is geared the driving portion of a positively engageable clutch mechanism, the driven portion of which is secured to a shaft that times and performs the operations of the tape controlled apparatus. The clutch through which the timing and operating power is transmitted is of the spring loaded type which is arrested by moving a clutch throwout lever into the path of a stop lug with which the throwout lever cooperates to effect separation of the clutch elements. The clutch throwout lever is spring biased toward ineffective position.

The power -shaft to which the operating shaft is geared has secured to it the driving portion of a smaller and lighter duty positive drive clutch mechanism, and the spring loaded driven portion of the clutch mechanism is free on the power shaft and is keyed to a cam sleeve which carries a camagainst which rides a cam follower. 'Ihe cam follower is associated with a lever which is operable to present the previously mentioned clutch throwout lever in the path of the stop lug to effect arrestment of the timing and operating shaft. When the cam controlled lever falls away from the clutch throwout lever, the biasing spring of the latter withdraws it from blocking relation to the clutch throwout lug, and the operating shaft is permitted to be restarted.

The light duty clutch is controlled by a lever having two clutch throwout arms presented ap-` proximately 180 degrees apart with reference to 193s, serial No. 195,509'

(c1. 19a-1s) the driven portion of the clutch. A single clutch l throwout cam carried by the driven portion of the light duty clutch engages the arms of the clutch control lever alternately to effect arrestment of the cam after one-half revolution thereof. The clutch throwout lever is controlledby a tape responsive lever whichhas a loop through which the tape passes to the tape controlled mechanism, and the tape engaging end-of the tape responsive lever is lifted and lowered as the tape becomes /taut or slack.

For. a Acomplete understanding of the invention, reference may be had to the following detailed description to be considered in conjunction with the accompanying drawing wherein,

Fig; 1 is a schematic perspective view of a tape controlled apparatus including a tape stop mechanism according tothefpresent invention;

' Fig. 2 is an elevational view partly in section of the tape controlledmechanism and tape responsive power stop control shown in Fig. 1; and

Fig. 3 is a diagrammatic view showing the relation' of the tape controlled mechanism to its source of control tape, and the relationship of the tape responsive lever arm to both instrumentalities. v

The taut and slack tape mechanism, according to the present invention, has been disclosed herein as applied to a tape controlled operating unit for a linecasting and composing machine as disclosed in Patent No. 2,091,286 granted August 31, 1937 to H. L. Krum et al.

Referring now to the drawing in which like l designated as a record reader shaft. Gear I6 is` secured to a sleeve i8, which is freely rotatable upon shaft i1 independently thereof, and which is provided with square cut clutch teeth I9. A similar sleeve 2l is slidably keyed to shaft Il and is provided with square cut clutch teeth 22 presented toward clutch teeth I9 for cooperation. therewith. f

A compression spring 23 urges driven clutch sleeve 2| to engage driving clutch sleeve I8.

Driven clutch sleeve 2| .is provided with a clutch throwout, lug 2l forcooperation with which 'a clutch throwout lever 26 is pivoted on pivot rod 21. Clutch throwout lever 26 is provided with an aperture 28, which lug 24 is adapted to enter when lever 26 is rocked into its path, and aperture 28 has one wall disposed in an oblique plane to exert a camming effect upon clutch throwout lug 24 and shift driven clutch sleeve 2| axially upon shaft I1 out of engagement with driving sleeve I8.

Clutch throwout lever 26 carries a spring post 29 which is engaged by one end of a ension spring 3| the other end of which is supported by a fixed spring post 3l). `Spring 3| is effective to withdraw clutch throwout lever 26 out of the path of lug 24 and to hold it out when it is desired that shaft I1 shall be rotated continuously. A lever 32 for controlling clutch throwout lever 26 is also pivoted upon pivot rod 21 and carries at its free end an adjustable abutment screw 33 through which movement may be imparted to clutch throwout lever 26 in a direction to effect arrestmenty of lug 24. Lever 32 has a laterally extending ear 35, the lower edge of which is arcuate to provide a cam surface. A rock shaft 34, provided externally of the apparatus with a. handle (not shown), carries an ftrm 36 at the free end of which is supported an anti-friction roll 31. ArmA 36, when presented in horizontal position, engages a portion of the arcuate lower edge of ear 35 which permits lever 32 to retire to its extreme counterclockwise position, under which condition clutch throwout lever 26 may also occupy its extreme counterclockwise position, out of the path of lug 24. When rock shaft 34 is rocked counterclockwise, anti-friction roll 31 traverses the arcuate lower edge of ear 35 and rocks lever 32 in clockwise direction. Lever 32 imparts clockwise rotation to clutch throwout lever 26 through abutment screw 33 and rocks the clutch throwout lever into extreme clockwise position to arrest driven clutch sleeve 2 I.

Shaft I1 has secured thereto a cam 38 which is engaged by anti-friction roll 39 carried by detent lever 4| pivoted upon stud 42. Detent lever 4| is biased clockwise, as viewed from the foremost end of shaft I1, by spring 43, and cam 38 is provided with a sharp drop-01T which is presented to anti-friction follower roller 39 at about the instant separation of clutch sleeves I8 and 2| is effected by cooperation of lug 24 with aperture 28 of clutch throwout lever 26. The function of detentl4| is to impart to shaft I1 a torque at thel time of separation of the clutch elements so that slight additional axial movement shall be imparted to clutch sleeve 2|, and rubbing of the teeth and accompanying noise and wear during periods of arrestment of shaft I1 shall not occur.

Shaft I1 also has secured thereto cams 46, 41, and 48 which control tape feeding, tape sensing, and signal transferring operations. Cam 46 is engaged by a follower roll 49 carried by one end of a pivoted tape feed lever 5I which has at its opposite end a pawl (not shown) to operate a ratchet (also not shown) carried by tape feed shaft 52. Shaft 52 has secured thereto a tape feed sprocket 53 which engages feed perforations 54 in the control tape 50 and which advances the tape one step for each operation of tape feed lever 5I, the lever being operated once for each cycle of rotation of cam 46.

A plurality of tape sensing levers 56 are rockably mounted upon a pivot rod 51 and are provided adjacent to the point of pivotal mounting with oppositely extending arms 58 and 59. Arms 58 are provided with individual upstandng tape sensing pins 6| which are adapted to enter code perforations in control tape 50, there being a tape sensing lever 56 and pin 6| for each of the possible perforations in a code combination. A bail 62 carries a rod 63 which extends 'across under all of the arms 59 of tape sensing levers 56. Bail 62 is operated by cam 41 through cam follower arm 64 carrying follower roll 66, and the operation of the bail is such as to lift rod 63, which. engages arms 59 of the tape sensing levers 56, and rocks the levers clockwise about pivot rod 51, thus withdrawing tape sensing pins 6I from code perforations in tape 50. After the ta'pe sensing pins have been withdrawn, tape 50 is advanced under the control of cam 46, and thereafter bail 62 lowers rod 63, and levers 56 respond to their biasing springs 61 and seek to present their sensing pins 6| in code perforations in tape 50. All of the tape sensing levers 56 rock counterclockwise a short distance, and those, the tape sensing pins which encounter imperforate portions of tape 50, are arrested, While those which nd perforations continue in counterclockwise direction until their pins have entered the perforations. A stop rod 68, extending through oversize apertures in tape sensing levers 56, limits the movement of the levers in tape sensing direction and also in sensing pin withdrawing direction. At their lower ends, tape sensing levers 56 are provided with spaced leftand right-hand abutment arms 69 and 1|, respectively.

Below tape sensing levers 56, a set of T-shaped transfer levers 12, equal in number to the number of tape sensing levers 56, is pivotally supported upon a rod 13 carried by a transfer bail which has been omitted from the drawing for the sake of simplicity. Transfer levers 12 are provided with leftand right-hand upstanding abutments 16 and 11, respectively, the spacing between which is sufficiently greater than the spacing between arms 69 and 1| of tape sensing levers 56 that the left-hand abutments 69 and 11 of the tape sensing levers 56 and transfer levers 12, respectively, may be in vertical alignment, or the righthand abutments of those levers may be in alignment depending upon whether a tape sensing pin 6| is engaging an imperforate portion of tape 50 or has entered a perforation. After cam 41 has operated to permit tape sensing levers 6| to seek admission into the code perforations in the tape, rod 13, which supports the transfer levers 12, is lifted by the transfer bail (not shown), which is operated by cam 48, to bring the transfer levers into engagement with the tape sensing levers 56. 'Ihose of the transfer levers 12 that engage tape sensing levers, the pins 6| of which have encountered imperforate portions of the tape, are rocked counterclockwise, and those of the transfer levers which engage tape sensing levers, the pins 6| of which have entered code perforations, are rocked clockwise.

Transfer levers 12 have depending arms 18 which terminate in disc-like portions that are fitted into slots contained in the right-hand ends of code bar extensions 19. At their left-hand ends, extensions 19 engage permutation code bars 8|, the number of code bars and code bar extensions being the same as the number of transfer levers, tape sensing levers, and the possible number of perforations in a signal combination. The upper and lower edges of code bars 8| are notched permutatively, and selectable bars 82 are pivotally mounted upon a common pivot rod 83 so as to ex, tend across the set of code bars".8|, some beingv Presented to seek engagementv with the upper" amasar `tape sensing levers 58 results in corresponding leftward or rightward presentation of code bar extensions 19 and code bars 8| For each characteristic setting of code bars 8|,l undei` the control of tape sensing levers 88, an alignment of notches is presented to one of the selectable bars' 32 which may respond to its biasing spring 84 and enter the alignment of notches. The operations occurring following the entry of a selectable bar 82 into an alignment of notches are not disclosed herein, but it may be learned by reference to the hereinbefore identified patent that the selectable bar thus moves into the path of an operating bail by which it may be operated to perform any desired function, such as for example, the operation of a weight bar in a iinecasting and composing machine to effect the release of a matrix. It may also be learned by reference to that patent that the operating bail is operated by shaft l1 and that' there is a stripper bail also driven by shaft I1 which lifts a selected bar 82 out of the alignment of notches after it has been operated, and which lifts all of the other selectable bars out of engagement with the edges of code bars 8| to remove any frictional resistance which the selectable bars may exert upon code bars 8l to permit the code bars to be set according to the next signal combination sensed by tape sensing levers 56 and transferred by operation of cam 48.

The apparatus described in the foregoing pages includes no portion of the present invention except as invention may reside in the combination of the apparatus described above with the mechanism to be described later, but the description is set forth briefly in order that the nature of the invention and its relation to a tape controlled apparatus may be understood. A much more complete disclosure and description of the apparatus hereinbefore described may be found in the previously mentioned Patent 1 No. .2,091,286 to H. L. Krum et al.

When the tape controlled mechanism heretofore described is to be controlled by tape prepared in substantial quantity in advance, the tape controlled mechanism may be permitted to operate substantially continuously until the supply of tape has been exhausted and no power stop control is required. However. it may sometimes be desirable to operate the tape controlled apparatus by tape prepared in accordance with signals received from a distant point over a telegraph line. Such an arrangement is indicated diagrammatically in Fig. 3, wherein reference numeral 36 designates a keyboard operated tape perforating mechanism for preparing control tape for controlling the generation of telegraphic signal impulses capable of controlling a tape apparatus, such as that shown in Fig. l, located at a point remote from perforator 86. The tape prepared by the perforator is indicated 81, and after being delivered from perforator '86, it enters a tape controlled telegraph transmitter 88. Keyboard tape perforator 36 may be of the type disclosed in Patent No. 2,059,250 granted November-3, 1936 to H. L. Krum, and tape transmitter 88 may be of the type disclosed in Patent No. 1,460,357 granted June 26, 1923 to E. E. Kleinschmidt. IIxransmitter 88 impresses upon telegraph line 89 signals according to the 4code combinations contained in tape 81. At the receiving end of the telegraph line 89. a reperforator 9| is connected. which may be of the type disclosed in Patent No. 1,884,743 granted October 25, 1932V to E. E. Kleinschmidt. The function of repertorator 9| is to prepare the perforated tape, which has already been designated by the reference numeral 58, to control the record reader 'mechanism of Fig. 1.

It is characteristic of telegraph transmitting systems in whichvthe transmission is controlled by tape'fed directly from a keyboard operated perforator to the transmitter that the time lag between preparation of the tape and transmission of the signals contained in the tape may be so small that any material interruption `in the operation of the perforator lmay result in arrestment of the transmitter, which will also result in cessation of telegraphic transmission and arrestment of reperforator 9|. With the reperforator inactive, it is necessary to arrest the tape sensing and tape controlled apparatus as soon as any slackness of tape between the 'reperforator and the tape sensing mechanism has been taken up, in order that the tape shall not be severed nor feed perforations or code perforations destroyed by attempting to feed'the tape through the tape sensing mechanism after the tape has become taut. The apparatus about to be described is intended to effect arrestment of the previously described tape controlled apparatus when the tape has become taut.

As shown in Fig. 1, continuously driven shaft Il has secured thereto the driving element`92 of a positive drive clutch mechanism. The driven element 93 is slidable axially of shaft Il for engagement with and disengagement from driving element 92 and is keyed to a cam sleeve 94 which is supported by shaft Il but is free of said shaft so that it may be held stationary while shaft Il is rotating. A compression spring 96 confined betweencam sleeve 94 and driven clutch element 93 urges the clutch element into engagement with driving element 92. Driven clutch element 93 carries a single clutch throwout cam 91 which is adapted to be engaged by either of two arms 98 and 99 of a clutch throwout lever |01. Clutch throwout lever IOI is pivoted upon shoulder screwl02 carried by bracket |83. The free ends of the two arms 98 and 99 of clutch throwout lever lill are presented substantially at diametrcally opposite points relative to driven clutch elementl 93, and the spacing between the free ends of arms 98 and 99 is such that either may be presented in the path of clutch throwout cam 91, the upper arm 98 being in the path of cam 91 when clutch throwout lever IUI is presented in its extreme counterclockwise position, as viewed in Fig. 2, and the lower arm 99 being presented in the path of the cam 91 when lever Illl occupies its extreme clockwise position. As soon as one of the arms of lever 18| is drawn out of blocking relation to cam 91, the other is presented linto the path of the cam. the two-armed clutch throwout lever.

and driven clutch element thus operating similarly to an escapement, so that driven clutch element 93 cannot rotate more than one-half revolution before being arrested by cooperation of throwout' cam 91 with one of the lever arms 98 and 99. The contour of cam 91 is such that when it engages either of arms 98 or 99, drivenclutch element 93 is shifted axially of shaft Il out of engagement with driving element 92.

The end of lever I0| opposite to that which.'

carries arm 98 and 99 is disposed in a slot cut in one end of a lever |04 pivotally supported by v a shoulder screw |06 upon bracket .|01. The slot is cut in lever |04 at the left-hand end, as viewed -in Fig. 1, and atthe right-hand end, lever |04 supports an arm |08' which is several times as long as the distance from the point at which lever |04 is pivotally supported to its slotted end. The free end of arm |08 is formed into a loop |09 through which tape passes in traveling from reperforator 9|, shown in Fig. 3, to tape feeding sprocket 53 in the tape controlled apparatus.

Cam sleeve 94 has secured thereto a cam which may, if desired, be a simple eccentric so positioned upon the cam sleeve that in one `position of arrestment of driven clutch element 93, the portion of cam of shortest radius is presentedupwardly, and when driven clutch ele-` ment 93 is arrested 1n its other position, the portion .of cam I of longest radius is presented upwardly. A further requirement upon theorienta- `tion of camor eccentric I I with respect to driven clutch element .93 is that the portion of longest radius shall be presented upwardly when clutch Aelement 93 is arrested by the lower clutch throwout arm 99, and the portion of shortest radius shall be presented lupwardly when the clutch `mechanism is arrested by the upper throwout A||3 and is provided with an arm II6 (Fig. l)

which carries a cam follower roll I I1 which bears continuously against cam or eccentric A similar bail shaped lever I|8 is also supported by shaft ||3 in opposed relation to bail shaped lever ||2, a compression spring yI I9 being interposed between bail shaped levers II2 and I|8 and being retained in position by a screw |2I which passes through a clearanbe hole in lever II8 and threadedly engages lever I|2. Bail shaped lever II8 is provided with an upwardly extending arm |22 which engages clutch throwout lever 26 for the record reader shaft clutch comprising driving .element I8 and driven element 2|. When cam follower II1 is lifted to its highest position by cam or eccentric ail shaped lever ||2 is f rocked and the rocking movement is transmitted to bail shaped lever ||8 through yield spring ||9 whereby arm |22 rocks clutch throwout lever 26 in clockwise direction, as viewed in Fig. l, to effect arrestment of the record reader clutch driven element 2|. When cam III is rotated 180 deg-rees from this position, follower roller II1 is lowered, arm |22 falls away from clutch throwout lever 26, and tension spring 3| withdraws the clutch throwout lever from blocking relation to clutch throwout lug 24. Cam sleeve 94 is provided with diametrically opposed recesses |23 and |24 with which there cooperates a detent roller |26 secured to the free end of a spring arm |21. Detent roller |26 enters recesses |23 or |24 when cam is `brought into either of the two positions in which it is intended to be arrested, and thus stopping of the cam ||I exactly in the desired positions is assured. i

In operation, when there is an excess of tape between reperforator 9| and the tape controlled mechanism, loop |09 of arm |08 is in its lowermost position, lever |04 is disposed in extreme clockwise position, and clutch throwout lever |0| is disposed in extreme counterclockwise position whereby its upper arm 98 is holding driven clutch I element 93 separated from driving element 92 upon shaft |I, cam follower roller I I1 occupies its lowermost position, lever arm |22 is in extreme counterclockwise` position, and the tape feeding and sensing operations are proceeding under control of continuously rotating shaft |1. 'I'his is the condition indicated in Figs. 1 and 2. If telegraph signals cease -to be received by. reperforator 9|, the feeding o f tape out of reperforator 9| will be stopped, and as tape feeding sprocket 53 in the tape controlled apparatus continues to advance the tape past the tape sensing positions, the loop of tape in which loop |09 of arm I 08 is presented will be takenup and loop |09 will be lifted step by step, thus resulting in counterclockwise rocking of lever |04. The arcuate movement of the slotted end of lever |04 is very small as compared with the arcuate travel of loop |09 whereby a multiplication of forces is obtained.

sults in clockwise rocking of lever |0I, and even- *tually the loop of tape 50 becomes sufiiciently small to lift arm 98 of clutch throwout lever |0| out of restraining engagementl with clutch throwout cam 91. Driven element 93 thereupon moves into engagement with driving element 92, and cam is rotated degrees whereupon clutch element 93 is arrested by the lower arm 99. of clutch throwout lever |0|, the two arms 98 and 99 operating in the manner of an escapement to permit rotation of cam in half a revolution step. The rotation of cam III through 180 degrees results in lifting of cam follower I1, which `as previously described, effects rocking of clutch throwout lever 26 into position to arrest record reader shaft I1. Compression spring |I9 provides a yield so that there will be no damage to the apparatus should clutch throwout lug 24 be presented in position to block clutch throwout lever 26 when that lever is moved toward its clutch arresting position. The tape controlled mechanism will be arrested when lug 24 enters aperture 28.

When subsequently reperforator 9| begins to operate, a loop of tape will begin to form, and as loop |09 of arm |08 is lowered, lever |04 will be rocked clockwise, clutch throwout lever I0| will be rocked counterclockwise, and clutch throwout cam 91 will escape and revolve with driven clutch element 93 through one-half revolution, thus restoring cam ||I into the position shown in Figs. l and 2 and permitting clutch throwout lever 26 to be withdrawn by spring 3| so that shaft I1 may again be driven.

The work that shaft I1 is required to perform necessitates a relatively sturdy clutch mechanism for driving the shaft. Furthermore, considerable friction is developed between the square cut teeth of the driving element I8 and driven element 2|, and the clutch throwout mechanism is, therefore, required to be equally sturdy. It would be diflicult, if not impossible, to control clutch throwout lever 26 directly by the kind of tape that is ordinarily used for record purposes. However, by providing a control mechanism for the clutch throwout lever, which is power driven and which is provided through another and lighter clutch, and by providing a lever system for the control of the last mentioned clutch whereby a multiplication of forces is obtained, the relatively flimsy tape is enabled to control the light duty clutch, and this clutch in turn, capable of driving mechanism to control the heavy'duty clutch. Thus, an all mechanical tape stop mechanism is achieved by means of which a relatively thin and weak paper tape, which is further weakened by the perforation of signal combinations therein,

is enabled to control the heavy duty clutch through which power is transmitted for performing the tape sensing, feeding. signal transferring,

and function performing operations in aY tape control tape, means for connecting and discon.

necting said driving member to and from said .tape advancing and sensing means, and means\ actuated by power from said driving member for controlling said connecting and disconnecting means.

2. In a record tape controlled apparatus, a power operated shaft, a record reader shaft, `means actuated by said record reader shaft for giving effect to the tape records, a clutch mechanism for connecting said record reader l shaft to said power operated shaft,means operated by power from said power operated shaft for controlling said clutch, and means controlled in accordance with the path traversed by said record tape for controlling said clutch controlling means.

3. In a record tape controlled apparatus, a power operated shaft, means operated by said shaft for driving said tape controlled apparatus, means also operated by said shaft for controlling the driving of said tape controlled apparatus, and tape tension responsive means for controlling said last mentioned means.

4. In a record tape controlled apparatus, tape advancing and tape sensing means, means for giving effect to the tape records sensed, means for driving both of the means, means for disconnecting the driving means therefrom, means actuated by said driving means for operating said disconnecting means, and tape tension responsive means for controlling said operating means.

. 5. Ina record tape controlled apparatus, a power driven shaft, a record reader shaft, positive clutch means for connecting said record reader shaft to said power driven shaft, means controlled by said record reader shaft for advancing a record tape, means also controlled by said record reader shaft for giving effect to the tape records,` means for controlling the engagement and disengagement of said clutch means, positive clutch means for connecting said controlling means to vsaid power driven shaft, and means operative according to the quantity of tape available to said tape advancing means for controlling the second mentioned positive clutch means.

6. In a record reader mechanism, a power driven shaft, 'a record reader shaft, a positive drive clutch interposed between said shafts, a lever for controlling the engagement and disengagement of said clutch, a cam and follower for said clutch controlling lever, a clutch interposed between said power driven shaft andsaid cam, and means controlled by record material for controlling said last mentioned clutch.

"I. In a record reader mechanism adapted to i be controlled by a .record tape, a power driven shaft, a record reader shaft, a positive drive lclutch interposed `between said shafts, a lever for controlling the engagement and disengagement of said clutch, a cam and follower for said clutch controlling lever, a clutch interposed between said power driven shaft and said cam, means for imparting effectiveness to the last mentioned clutch in half-revolution cycles, and means responsive to the tension of said record tape for controlling the lastl mentioned means.

8. In a record reader mechanism adapted to be controlled by a record tape, a vpower driven shaft, a record reader shaft, a clutch interposed between said shafts, a cam eective in one position to control disengagement of said clutch and in another position to control engagement of said clutch, half-revolution clutchA means for presenting said cam in either of s aid positions, and means controlled according to the tension of said record tape for controlling said half-revolution clutch means.

9. In a record reader mechanism adapted to be controlled by a Irecord tape, a 4power driven shaft, a recordreader shaft, a clutch interposed between said shafts, means for controlling'the `engagement and disengagement of said clutch,

a cam for controlling the operation of said clutch controlling means, means for driving said cam, escapement means for controlling the rotation of said cam in half-revolution cycles, and tape tension responsive means for controlling said escapement means.

10.` In a record reader mechanism adapted to be controlled by a record tape, a power driven shaft, a record reader shaft, a clutch interposed between said shafts, a cam effective in one posi- 'tion to control disengagement of said clutch and in another position to control engagement of said clutch, means for driving said cam, escapement means for controlling the rotation of said cam in half-revolution cycles, detent means for maintaining said cam in the desired stop positions, and tape ltension responsive means for controlling said escapement means.

11. In a 'record reader mechanism adapted to be controlled by a record tape, a power drivenA shaft, a record reader shaft, aclutch interposed between said shafts, a cam effective to control the engagement and disengagement of` said clutch, means for driving said cam, means for releasing said. cam for rotation and for arresting said cam in predetermined positions, and means engaging said record tape and responsive to tension conditions therein for controlling said cam releasing and arresting means, said tape tension responsive means amplifying the force applied thereto by said tape.

12. In a tape controlled apparatus, a power operated shaft, a shaft to beA driven therefrom, a clutch mechanism interposed between said shafts, means operated by said driven shaft for actuating said tape controlled apparatus, means also driven from said power operated shaft for controlling said clutch, and tape loop responsive means for controlling said last mentioned means.

13. In a tape controlled apparatus, a power sponsive means for controllingv said last mentioned means.

15. In a tape controlled apparatus, power means, means for advancing and sensing a control tape, means for communicating power from said power means to said advancing and sensing means, and means actuated by said power means for controlling said power communicating means and accordingly the power communicated to said advancing and sensing means.

- KIM'MEL A. SYLVESTER. 

